CZ20002123A3 - Stackable chair - Google Patents

Abstract

A stackable chair has a frame with a tubular crosspiece (18), to each end of which a monolithic casting (FC) having a leg (12l, 12r, 14l, 14r) and a backrest support (16l, 16r) - and, optionally, armrests (122l, 122r) - is attached by means of an integral connecting boss (100) received within the crosspiece and held in place by a connector pin (30). The backrest supports receive a backrest (50) that pivots about a pivot pin (62) between an upright position, to which it is biased by a spring (54), and a rearwardly tilted position. The range of tilting motion is limited by a stop pin (68) on the backrest and a stop groove (64) in the backrest support. A seat (24) is mounted on the crosspiece, either in a fixed position or for tilting to an upright position. Chairs with tilting seats include seat supports (28) having diametrically opposite slots (38, 40) that receive projecting portions of the connecting pins. The connector pins slidably engage the sides of the slots to hold the seat supports in place on the crosspiece axially. The ends of the slots engage the connector pins in the down and tilted-up positions of the seat. <IMAGE>

Description

(57)

A stackable chair comprising a tubular crossmember frame (18) to each end of which is attached a monolithic cast (FC) having legs (121,12r, 141,14r) and backrest supports (161,16r,) and optionally armrests (1221) , 122r) - fixed by means of an integral connecting protrusion (100) inserted into the cross-member (18) and held in place by the connecting pin (30). The backrest supports may slide the backrest (50) that rotates around a pivot (62) between an upright position in which it is biased by a spring (54) and a rearward inclined position. The range of tilt is limited by the stop pin (68) on the support and the stop groove (64) in the backrest support. The seat (24) is mounted on the crossmember, either in a fixed position or for tilting in an upright position. Tilting-chair chairs include seat supports (28) having diametrically opposed slots (38, 40) into which protruding portions of the dowel plugs. The connecting pins slidably engage the sides of the slots so as to hold the seat supports in place, axially on the crossbeam. The ends of the slots engage the dowel pin in the lower and upward tilt position of the seat.

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01-1673-00-Eng

Stackable chair

Field of the invention

The present invention relates to a stackable chair.

BACKGROUND OF THE INVENTION

Stackable chairs are often used in a variety of institutions or commercial establishments of all kinds, such as meeting and conference rooms, lecture halls, multi-purpose banquet halls and gyms, which can be temporarily converted into lecture halls. Stackable chairs take up little storage space, providing space for other purposes.

Most stackable chairs have a fixed backrest that is comfortable for one seating position but not comfortable for other positions than the one it is designed for. Seated quickly get tired if he cannot change the seating position from time to time. Chairs with a fixed backrest are therefore inconvenient for much of the time a seated user spends on them.

Stackable chairs usually have fixed seats. Rows of chairs with fixed seats shall be spaced at relatively wide intervals to allow people to easily walk along the aisles between the rows. The wider spacing of chairs reduces seating capacity for any given space.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a stackable chair that is comfortable to sit in many positions, attractive in appearance, highly durable, versatile and economical to manufacture. Another object of the present invention is to provide a stackable chair that could be assembled easily and quickly by an inexperienced user, using only simple tools, which would allow the chair to be disassembled to the point of sale or use. It is also desirable that the stackable chair can be used in a variety of ways to suit the needs and requirements of individual users. Another object of the present invention is to allow stacking chairs to be arranged in close rows, which would result in a higher occupancy density.

The above objects are therefore accomplished in accordance with the present invention, in the form of a chair comprising a crossmember and a front foot, a rear foot and a backrest support fixed to both ends of the crossmember, a crosshead seat, a backrest and a pair of backrest mounted mechanisms. by which the backrest is fastened to the backrest support for pivotal movement about the axis of the horizontal pin between an upright and a rearward inclined position. Each said backrest mounted mechanism attaches one side of the backrest to the backrest support. In particular, the backrest mounted mechanism comprises a pivot pin connecting the backrest to the backrest support for pivotal movement, a spring positioned between the backrest and the backrest support and tensioning the backrest to an upright position, a stop pin mounted either to the backrest or to the backrest support and slid into the stop groove in the backrest support

back or backrest. The stop pin engages the stop surface of the stop groove so as to limit the extent of the pivoting movement and establish an upright and inclined position of the backrest.

As is well known, fastening the backrest of the chair for pivotal movement allows the backrest to take any position between an upright and significantly inclined rearward position, as a result of the force exerted on the back of a person sitting on the chair, resulting in a comfortable back support. The backrest fastening elements used in the present invention are of simple construction, easy to install, cheap, durable and require little space.

Advantageously, a torsion spring with a thread and protruding arms at each end of the thread may be used, the thread being slid onto a pivoted pivot, one arm sliding into a cavity in the backrest and the other arm sliding into a cavity in the backrest support. In addition, the cavity in the backrest may be provided in the lateral, outwardly facing surface of the backrest and the cavity in the backrest support may be formed in a surface facing inwardly of the backrest support, in line with the surface facing outwards. In this way, the backrest fastener is concealed from the user's view.

For the stop pin it is preferred that it is fastened to the backrest and the stop groove is formed in the backrest support. The groove requires more space than the stop pin and is best formed in the backrest support, while the stop pin is easily supported in the backrest without requiring unduly enlarging the backrest dimensions in the mounting area. The mounting of the stop pin is facilitated in that the backrest support may have an opening directed into the stop groove aligned with the hole in the backrest into which the stop pin is inserted such that the stop pin can be installed from the side (outside) of the backrest support .

In a preferred embodiment of the chair according to the invention, the seat is secured to a pair of side seat supports fixed to the crossbeam. The seat supports may be fixed to the crossbeam, or they may be pivotally mounted on the crossbeam so that the seat can be tilted upwards. In one preferred construction, the cross-member is tubular and at least the front leg and the backrest support at each end of the cross-member are parts of a monolithic casting of metal, preferably aluminum. Each casting includes an integral fastening protrusion that slides into the end portions of the crossbeam. The fastening protrusion of each casting extends longitudinally into the cross-member and is fastened to it by means of a connecting pin that extends through holes in the cross-member and a fastening protrusion. Such an arrangement facilitates the manufacture and assembly of the chair frame, uses space efficiently and is solid. Each cast may also include a hind leg. It is also possible to have the hind legs separately and attached to the casting, which includes the front legs and supports. Desirably, the fastening protrusion of each casting includes an axial rib that slides into the slot in the crossbeam so as to ensure proper rotation and positioning of the protrusion in the crossbeam and further secures the casting to the crossbeam and secures it against rotation.

In addition to attaching the frame casting to the cross member, the dowel retains the corresponding seat support, for chairs that have the seats tilted upward, in the correct axial position on the cross member and serves as a stop for adjusting the lower and upper positions of the seat. To these ends, the connecting pin extends entirely through the crossbeam and includes portions extending outwardly from opposite sides of the crossbeam. The protruding portions are inserted into the stop slots in the seat support, are slidably mounted in the side surfaces of the stop slots, and hold

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9999 99 99 99 · 9 the seat support on the cross member and prevent it from laterally moving (axially along the cross member) and can engage the end abutment surfaces of the stop slots so that the seat support can be brought into the lower or upper position. The fastening of each frame cast and seat support and the stop function for the seat's tilting properties are achieved by a single element - a dowel - which is cheap, takes up little space and is easy to install.

Many chair users in which the invention will be used will be satisfied if the seat is tilted and tilted manually. Other users will find it desirable that the seat be tilted automatically if no-one is seated and the aisles between the chairs remain empty. These second users will be satisfied with a chair according to another object of the present invention, which is achieved by connecting the spring between the crossmember and at least one - but preferably both - seat supports to tension the seat and rotate it up. For example, a simple spring connecting the dowel and seat support may be used by tensioning the seat and pivoting it up.

Chairs according to the invention are designed to be stacked with the seat in the down position. Facilitating stacking of chairs with automatic seat straightening is provided by providing a locking pin mechanism on one seat support that locks the seat down. A preferred design is a locking pin that is normally elongated by the spring in the released position. The locking pin can be inserted into the tubular protrusion in the flange portion of the seat support and can move into the opening in the crossbeam and lock the seat in the down position. The seat spring forces which ensure its straightening are exerted through the locking pin, which is thereby absorbed by friction in the opening in the crossbeam. Such a design of the locking pin mechanism guarantees a downward force on the seat which eliminates the frictional engagement of the locking pin which jumps up and releases the seat so that it automatically tilts.

List of figures in drawings

In order that this invention may be better understood, as well as other features and advantages thereof, reference will be made to the following description of an exemplary embodiment, taken in conjunction with the accompanying drawings, in which:

Fig. 1 shows a frontal side view of a version of an embodiment of the invention with automatic seat tilt and without armrests, wherein the seat is in the "lower" position;

Fig. 2 shows a frontal side view of a version of the embodiment of the invention with automatic seat tilt and without armrests, where the seat is in the "up"

Giant. 3 shows a front view of the version of the embodiment of FIGS. 1 and 2;

Fig. 4 shows a left side view of the version of the embodiment of Figs. 1 to 3, wherein the seat is in the "down" position;

Giant. 5 shows a right side view of an embodiment of the present invention with armrests wherein the seat is in the "up" position;

Giant. 6 shows a partial front view of an embodiment of the left seat support and a part of the seat and cross member frame,

Giant. 7 shows a partial plan view of an embodiment of the left seat support where the seat is removed and a part of the cross-member frame;

Giant. 8 shows a partial cross-sectional side view of the side view of FIG. The left-hand seat support, where the cut is taken along line 8-8 of Fig. 6, · · · · · · · · · · ·

Fig. 9 shows a side rotational view showing the locking pin mechanism intended to secure the seat in the down position;

Fig. 10 shows a side sectional view similar to Fig. 9 showing the locking pin in the locked position;

Fig. 11 shows a front partial view showing the lower left portion of the backrest and the upper end of the left support of the backrest;

Fig. 12 shows a front partial view showing the lower left portion of the backrest and the upper end of the backrest support;

Fig. 13 shows a side rotated view showing the lower portion of the left side of the backrest (side view) as a mirror image of the right side;

Fig. 14 is a side view of the torsion spring of the backrest tilting mechanism;

Fig. 15 is a partial side elevational view showing the upper end of the backrest support that is positioned facing the backrest (environment view),

Fig. 16 is a partial cross-sectional elevational view showing the backrest tilt / stop mechanism taken along line 16-16 of Fig. 13;

Fig. 17 is a plan view of a seat support used to secure a seat in a chair version where the seat is fixed;

Fig. 18 is a left side elevational view of the seat support of Fig. 17, as a mirror image of the right side;

Fig. 19 is a front elevational view of the seat support of Figs. 17 and 18;

Fig. 20 to Fig. 26 are views of the left seat support, configured for different versions of the chair, where the seat is tiltable - the right chair support is the same except for the location • · φ φφ Φ ·

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ΦΦΦ ΦΦΦΦ Φ · Φ ·

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Flange parts:

Fig. 20 is a left side view,

Fig. 21 is a bottom view,

Fig. 22 is a plan view,

Fig. 23 is a frontal view,

Fig. 24 is a rear (enlarged) cross-sectional view taken along line 24-24 of Fig. 20;

Fig. 25 is a rear cross-sectional view taken along line 2525 of Fig. 20;

Fig. 26 is a rear cross-sectional view taken along line 2626 of Fig. 22;

Fig. 27 is a partial, rotated view of the left leg cast / backrest support,

Fig. 28 is a partial, sectional, cross-sectional view of the connection between the crosspiece and the left leg cast / backrest support;

Fig. 29 is a plan view on part left ends cross-section, part is cut, Fig. 30 is a front cross-sectional view on good final part backrest supports, and Fig. 31 is a detailed view on part casting left

legs / backrest supports

DETAILED DESCRIPTION OF THE INVENTION

The frame 10 of the chair-free version shown in Figs. 1 to 3 consists of a right hind leg 12r and a left hind leg 121, a right front leg 14r and a left front leg 141 and a right back support 16r and a left back support 161. The right legs 12r and 14r and the right backrest support 16r are parts of a monolithic aluminum casting and are connected to the right end of the crossbar 18, which is an ordinary steel tube cut to the correct length and having holes and slots (described below). Similarly, the left legs 121 and 141 and the left backrest 161 are parts of a monolithic aluminum casting and are connected to the left end of the crossmember 18. To simplify the expression, the casting that secures the legs and backrest supports (and armrests, see below) Generally referred to hereinafter as "FC Frame Casting" The right and left FC frames are identical except for the side.

The armrest version as shown in Figures 4 and 5 is the same as the armrest-free version, the only difference being that the right armrests 122r and the left armrests 1221 are integrally formed with the corresponding right frame casting FC and the left frame casting FC. It is not possible to stack the chair with armrests, however, it is advisable to stack the chair-free versions of the chairs on the armrests. The user may wish to have a mix of chair and armrest versions and can therefore stack one or more armrests without armrests on armrests

The seat 24, which may be made of metal, molded from plastic or composite material, or any other suitable material, is supported on the crossbeam 18 by a pair of seat supports 26 and 28 that are rotatably slid onto the crossbeam 18 so that the seat can rotate . The swivel feature allows people seated in a row of seats to stand up, manually lift the seat (or allow it to lift automatically as described below), move backward in the aisle between the rows of chairs, and allow other people to walk through that aisle more easily. The seats are preferably lifted up when the chairs are not occupied so that people can more easily walk down the aisle. The possibility of lifting the seat allows the rows of chairs to be placed closer to each other than with rows of chairs with fixed seats. However, versions of chairs with a fixed seat are also listed as is

4 • * · · * 44 4 4 44 4 _φ 4 4444 4 -4 4 4 • «44 * 44444 44 4 ** 44 * 4444

444 4444 44 44 44 44 described below. The seat supports 26 and 28 in the version of Figures 1 to 5 are cast aluminum. In addition, as shown below, both seat supports 26 and 28 are identical except for the side. Both seat supports 26 and 28 have springs that rotate the seat to the upright position automatically, except when someone is sitting on the seat or when it is locked in the lower position as shown below. However, it is sufficient to describe the left seat support 28 shown in FIGS. 6 to 10.

The seat support 28 has an elongated channel-shaped front support arm 28f, an elongated channel-shaped rear support arm 28r, both with side and bottom walls that form an upwardly open cavity and a tubular protrusion / flange portion 28b with an opening 28h receiving the cross member 18 with a sliding connection so that the seat support 28 can pivot about the axis of the crossbeam 18. The connecting pin 30 extends through holes in the wall of the crossbeam 18. Part of the lower end of the connecting pin 30 is reduced in diameter and thus actually has a shoulder intended to stop the pin in advance a specified position in the opening in the crossbeam. The protrusion / flange portion 26b of the seat support 28 has slots 38 and 40 into which the pin 30 is inserted. The pin 30 has portions protruding out of the cross member 18. The pin 30 slidably engages the side walls of the slots 38 and 40 and holds the seat support in The ends of the slots 38 and 40 serve as stops for the seat support 28 by engaging the pin in the up and down positions.

The dowel pin 30 also holds the frame casting FC on the crossbar 18 as described below in FIG. 28.

One end of the tension spring 32 is connected to the eye 34 of the arm 28f and the other end to the pin 30. The spring tensiones the seat to the up position as shown in broken lines in FIG.

• 4 • 4

One seat support, for example the left support 28, has a locking pin mechanism (see Figs. 9 and 10) at the upper rear end of the protrusion / flange flange portion 28b, where it is usually not visible. Into the tubular protrusion 40 on the protrusion / flange, the locking pin 42 is inserted by sliding movement, which is normally retained by the extended spring 44 in the stop position established by the stop pin 46 inserted into the stop slot 48 in the protrusion. The locking pin mechanism keeps the seat in the lower position where the chairs can be stacked. The operator holds the seat down and squeezes the locking pin, which moves into the opening in the crossbeam 18 (Fig. 10) and then releases the seat while the locking pin is still depressed. The forces of the tilt springs 32 (Figs. 7 and 8) on the seat supports 26 and 28 are applied by means of a locking pin 42, which is thereby secured by friction in a hole in the crossbeam 18. If the seat is locked in the lower position, the worker can stack the chairs. Once it is ready for use, the front side of the seat is pushed down, which cannot occur until someone is sitting on the chair, thereby releasing the force of the tilt spring 32 and eliminating friction holding the locking pin 42 in the locked position, thereby releasing the locking pin 42 from the seat. therefore, the seat is automatically raised when no force is applied to hold it down.

The backrest 50, which will usually be of the same material as the seat 24, is mounted on the backrest support 16r and 161 so that it can rotate between an up and back tilted position which makes the chair more comfortable due to different upright and slightly backward seating positions, crouched or forward inclined positions. The spring mechanism tensiones the backrest 50 to an upright position, and the stop mechanism limits the extent of movement of the backrest 50 between an upright and an inclined position. The spring and the stop mechanism connected to both armrests are identical except for the side. The following description of the left mechanism applies to both sides of the mechanism.

Each lower end of the backrest 50 has a notch 52 into which the upper end of the backrest support 161 is inserted (FIGS. 11 and 12). One leg 5411 of the torsion spring 54 and a portion of one thread 54c of the spring 54 are inserted into a groove 56 in the sidewall the backrest support 16 forming the notch 52 (Figs. 13 and 16) The spring coil 54c is retained in place by a tubular projection 53 on the backrest 50. The middle (inner) upper end of the backrest support 161 (Fig.15) it has a cavity 58 into which the second leg 5412 and the remaining spring coils 54c are inserted The pivot pin 62 has a smooth shaft that extends through an opening in the backrest support 16 and is secured to the back support 50 by the threads at the end (Fig. 16). The spring relieves the force exerted by the back of a person sitting on a chair when it tilts backward when the backrest is pivoted about the pivot 62.

The middle (inner) face of the upper end of the backrest support 16 has an arcuate groove 64 (see Figure 15) whose center of curvature is the pivot axis 62. The opening 66 through the bottom wall of the groove and the opening in the side face of the rear support allows the stop pin 68. to be inserted from the side of the backrest support 16 into the groove 64 and secured to the backrest 50 by screwing it into a hole prepared here. After the stop pin 68 has been installed, the plug 70 is pushed into the hole 66 to enhance the appearance. The stop pin 68 rotates with the backrest 50 about the pivot pin 62 to the extent allowed by the opposite ends of the groove 64.

The engagement of the stop pin 68 with the ends of the groove 64 leads to a stop of the pivoting movement of the backrest.

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As mentioned above, the chair may have a fixed seat instead of a folding seat. In this case, the seat supports 128 as shown in Figures 17 to 19 are used instead of the seat support 28 as described above. The seat supports 128 are punched and bent out of sheet metal and form a channel-like component similar to the profile as mentioned above as the seat support 28. The semicircular notches 130 on the side flanges 132 are adjacent the crossbeam 18. The seat supports 128 are welded to the crossbeam 18 at the same points as the hinged supports. The holes 134 in the base 136 receive bolts for attaching the seat to its support. The hole 138 in the base 136 allows the connection pin 30 to be installed.

Giant. 6 to 8 (described above) show the seat support 28 generally and schematically. 20 to 26 show the seat support 28 in more detail and in a view of the above description in an obvious manner. The seat support 28 is a casting, preferably made of aluminum. As can be seen in Figs. 22 and 25, the end surface 38ed and 40ed of the slots 38 and 40 in the flange portion 28b may engage the connecting pin 30. The slot is semi-cylindrical - these surfaces have the same diameter as the connecting pin, so the stresses between the connection pin and the end surface are kept low when engagement occurs. The surface 40ed and the flange portion 28b on which the surface is formed are made larger to be able to withstand a higher load when the seat is down. The 38ed and 40ed surfaces share the load when the seat is down. Top positions of the 38eu and 40eu seating positions can have any shape as long as the loads are low. The small protrusions 28s surround the screw holes that secure the seat 24 to the seat support 28. For automatic tilt of the seat •

• · · • · • 0 0 0 • 0 • 0 0 0 0 0 0 • · · • 0 0 0 0 0 0 0 0 '0 0 « 0 0 0 0 0 «* 0 0 0 0 0 • · • 0 «·

locking in the lower position no modification is made to the seat support 28 in Figs. 20 to 26. The seat support of Figs. 26 to 26 is designed for manual folding. For automatic folding it must only be modified to include a connection point for one end of the spring (see Fig. 7 and Fig. 8).

As mentioned above, the frame casting FC is provided with a leg 12 and a leg 14 and a backrest support 16 for the chair frame, and may also include armrests 122. The middle surfaces of the leg 12 and 14 and the backrest supports 16 have grooves 12g, 14g and 16g. .27) over most of their length which makes their profile generally grooved. The shaft-cylindrical protrusion 200 is integrally made at the joint of the foot and backrest support (see Figs. 27 and 28). The diameter centered apertures 102 and 104 are directed radially through the protrusion 100. The protrusion 100 slides telescopically by slidingly into a portion of the end of the tubular beam 18. The apertures 102 and 104 receive an interference fit connection pin 30 that retains the connection pin 30 in the installed position (see Fig. 8). The rib 106 on the portion of the protrusion 100 fits into the slot 18s in the crossbeam 18 (see Figs. 28 and 29) so as to properly orient the frame casting FC rotatably relative to the crossbeam in the correct position. The engagement between the rib 106 and the slot 18s also assists the connecting pin 30 to transmit peripheral loads transmitted from the crossbeam to the legs.

Fig. 30 shows the upper portion of the backrest support of the frame casting FC described above and shown in Figs. 15 and 16. It can be seen that the arcuate flange 60 protrudes slightly in the center from the middle face of the backrest support so as to establish a small gap between the side surface of the adjacent end of the backrest 50 and the middle surface of the backrest support 16.

• · · ♦

As shown in FIG. 31, the frame casting FC includes a recess 110 with ribs and grooves 112 from a side view of the leg joints 12 and 14 and the backrest support 16. The threaded hole 114 is located at the base of the recess. The recess is configured to accommodate a variety of accessories, such as connecting fittings, which allow chairs to join side by side, support elements, or arm support elements separate from the FC frame casting, and support arms for the desk, which are fastened to the frame casting by FC screws inserted into the threaded hole 114. If no accessory is installed in the recess 110, the decorative blank 116 is pushed into it (see Fig. 1a).

The chair has been designed to facilitate its assembly using simple tools so that it can be transported in a disassembled state, thus allowing significant savings in packaging and transport costs. First, the seat supports 28 (if used instead of the fixed seat supports 128) are inserted into the crossbeam 18. The frame castings are then partially mounted on the crossbeam 18 by inserting the protrusions 100 partially but not completely into the ends of the crossbeam 18. Springs 54 are inserted into the slots 58 in supports 16 of the backrest. At this time, of course, the springs are released so that the spring leg 5411 projects obliquely down and back relative to the axis of rotation of the backrest.

The fitter positions the backrest above its installed position, with the grooves 54 aligned with the spring leg 5411 and then pushes the backrest down between the springs along the leg line 5411. With less maneuvering, the spring will slide into the groove 52 in the backrest. The fitter then slips the pivot pin 62 into the threaded hole in the backrest and rotates the headrest to an approximate center between the upper and rear inclined position to tension the springs 54 and align the hole 66 in the backrest 50. The installer then installs the stop pin 70 in the holes 69 in the backrest. The frame casting can then be pushed fully into place in the crossbeam. The seat supports are shifted to the correct position axially so that the dowel slots 38 and 40 are aligned with the holes in the crossmember and the protrusions 100 of the frame casting. The dowel pins 30 are then installed using a hammer or mallet (since there is an interference fit). At this point, the pivot pins for the backrest can be tightened and the plugs or accessories, if used, can be installed in the recesses. All that remains is to secure the seat to the seat supports 26 with two screws 90 inserted through each seat support 28 (or seat support 128) in the seat. The assembly is now complete.

Fc fc fc fc fcfc fc fc fc fcfc fcfc fcfc fcfc fc fcfc fcfcfc fcfc fc fcfc

Frame Casting List FC, Frame 10, Left Rear Leg 121, Right Rear Leg 12r, Grooves 12g, Right Front Leg 14r, Left Front Leg 141, Grooves 14g, Backrest Support 16, Backrest Support 161, Backrest Support 16r , grooves 16g, crossmember 18, slot 18s, seat 24, seat support 26, protrusion / flange portion 26b, tubular protrusion / flange portion 28b, seat support 28, canal-shaped extended front support arm 28f, extended-form rear support arm 28r channel, aperture 28h, protrusion 28s, dowel 30, tension spring 32, eye 34, slot 38, end surface 38ed, 0u0 surface 38eu, slot 40, end surface 40ed, surface 40eu, locking pin 42, spring 44, stop pin 46, stop slot 48, backrest 50, notch 52, backrest 53, spring 54, spring thread 54c, spring leg 5411, spring leg 5412, groove 56, hollow 58, bend flange 60, pivot 62, stop groove 64, bore 66, stop pin 68, stopper 70, screw 90, bores 102, bores 104, rib 106, recess 110, groove 112, threaded bore 114, decorative bumper 116 , armrest 122,

left armrest 1221, right armrest 122r, seat support 128, semicircular notches 130, side flanges 132, bore 134, base 136, protrusion 200,

Claims (20)

PATENT CLAIMS 9 9 · 9 9 199 9,999 9 A chair comprising a crossmember (18) and a front leg (141, 14r), a rear leg (121, 12r) and a backrest support (161, 16r) mounted on both ends of the crossmember, further a seat (24) mounted on the crossmember, the backrest 50) a back and a pair of mechanisms mounted on a backrest (50) securing the backrest (50) to the backrest support (161, 16r) for pivotal movement about the horizontal pin axis between an upright and a rearward inclined position, each said backrest mounted mechanism (50) attaching one side of the backrest (50) to a support characterized by being mounted on a backrest (50) (161, 16r), by the back mechanism comprising a pivot (62) connecting the backrest (50); 50) a back to the backrest support (161, 16r) for pivotal movement, a spring (54) engaging between the backrest (50) and the backrest support (161, 16r) and tensioning the backrest (50) to an upright position; stop pin (68) attached b either to the backrest (50) or to the backrest support (161, 16r) and inserted into the stop groove (64) either in the backrest support (161, 16r) or in the backrest (50), the stop pin (68) engages a stop surface of the stop groove (64) so as to limit the extent of rotational movement of the backrest (50) and establish an upright and inclined position of the backrest (50). Chair according to claim 1, characterized in that the spring (54) is a torsion spring with a thread (54c) and protruding arms (5411 and 5412) at each end of the thread (54c), the thread (54c) sliding around a rotated one arm is inserted into the cavity (58) in the backrest (50) and the other arm is inserted into the cavity (56) in the backrest support (161, 16r). «·· ···· Chair according to claim 2, characterized in that the cavity (56) in the backrest may be provided in the lateral outwardly facing surface of the backrest (50) and the cavity (56) in the backrest support (161, 16r) may be made in a surface facing inwardly of the backrest support (161, 16r), in line with the surface facing outwards. Chair according to claim 1, characterized in that the stop pin (68) is fixed to the backrest (50) and the stop groove (64) is formed in the backrest support (161, 16r), further comprising a support (161, 16r). 16r) the backrest has an opening (66) directed into the stop groove (64) aligned with the opening in the backrest (50) into which the stop pin (68) is inserted such that the stop pin (68) can be installed from the side (outer) sides of the backrest support (161, 16r). Chair according to claim 1, characterized in that the seat (24) is fastened to a pair of seat side supports (28, 128) fastened to the cross member (18). 6. Chair according to claim 5., confesses č u j í c í se that to the crossbeam (18). armrests ( 128) seats j sou fastened 7. Chair according to claim 5., confesses č u j í c í se in that the seat supports (128) are rotatably mounted on the cross-member (18) so that the seat (24) can be tilted upwards. Chair according to claim 1, characterized in that the cross member (18) is tubular and at least the front leg and the back support at each end of the cross member (18) are parts of a monolithic metal casting (FC), each casting (FC) comprising a fastening protrusion (100) which slides into the end portions of the cross-member (18). Chair according to claim 8, characterized by 9 · 9 9 9 99 99 9 99 99, in that the fastening protrusion (100) of each casting (FC) is fixed to the cross-member (18) by means of a connecting pin (30) which extends through the holes in the cross-member (18) and the fastening protrusion (100). Chair according to claim 8, characterized in that each casting (FC) also comprises a backrest support (161, 16r). Chair according to claim 9, characterized in that each fastening protrusion (100) of each casting (FC) comprises an axial rib (106) which slides into the slot (18s) in the crossbeam (18) so as to further fasten the casting (FC) to the crossbar (18) and secures it against rotation. Chair according to claim 7, characterized in that for each seat support (28, 128) the connecting pin (30) extends entirely through the cross-member (18) and comprises parts protruding out from opposite sides of the cross-member, the protruding parts being slid into the stopper slots (38, 40) in the seat support (28, 128) are slidably mounted in the side surfaces of the stopper slots (38, 40) and hold the seat support (28, 128) on the cross member (18) and prevent lateral movement thereof (axially along the cross-member) and engage the end abutment surfaces (38eu, 38ed, 40eu, 40ed) of the stop slots (38, 40) so as to be able to bring the seat supports (28, 128) to the lower or upper position. The chair of claim 7, further comprising a spring (32) connected between the crossmember (18) and at least one seat support (28, 128) tensioning the seat such that it rotates to a tilted position. Chair according to claim 9, characterized in that for at least one seat support (28, 128) it comprises a tension spring (32) connected between the connecting ΊΤλ. • ft ftft »· · < ft ftft «ft · ftft ftft • ftft 1 • ftft« • · • · • ftft ftftftft • · • · • · ftft ftft pin (30) and support (28, 128) seat so that rotates seat (24) to the tilted position. Chair according to claim 5, v y z n a č u j ici s e by 2 one of the supports (28, 128) has seats mechanism locking pin (42, 44) 46), who it locks the seat (24) in the lower position. Chair according to claim 11, characterized in that the locking pin (42, 44, 46) is normally extended by the spring (44) in the released position. Chair according to claim 12, characterized in that the locking pin (42, 44, 46) is inserted into the tubular protrusion (40) in the flange part of the seat support (28, 128) and can be moved into an opening in the cross-member (18). ) and secure the seat (24) in the lower position. Chair according to claim 11, characterized in that the spring forces in the at least one support (28, 128) the seats act through the locking pin, which is thus captured by friction in the hole in the crossbeam (18) Chair according to claim 7, characterized in that the cross-member (18) is tubular, the front leg and the rear support at both ends of the cross-member (18) being parts of a monolithic casting (FC), each casting (FC) comprising a fastening protrusion (100). ) which is inserted into the end portions of the cross-member (18) and is fixed to the cross-member (18) by means of a connecting pin (30) which extends through the holes in the cross-member (18) and the fastening protrusion (100). and comprising portions extending outwardly from opposite sides of the cross-member (18), the projecting portions being inserted into the stop slots (38, 40) in the seat support (28, 128) and slidably engage the side surfaces of the stop grooves (64) to retain the seat support (28, 128) on the cross member (18) against lateral movement and further engage the end stop surfaces • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • seat supports (28, 128). The chair of claim 19, wherein each casting (FC) further comprises a backrest support (161, 16r). The chair of claim 19, wherein each cast (FC) further comprises an armrest (1221, 122r). Chair according to claim 19, characterized in that the fastening protrusion (100) of each casting (FC) comprises an axial rib (106) which is inserted into the slot (18s) in the crossbeam (18) so as to further secure the casting ( FC) to the crossbar (18) and secures it against rotation. The chair of claim 19, wherein each casting (FC) further comprises a recess (110) open outwardly adapted to receive an accessory.